Help! 2 stroke problem

**Reevesy** · 21st November 2006, 21:26

Hey.

I'm having some problems with my bike. I'll start at the start. I brought a KR1-S, running fine for a while, then I noticed it started running quite rough. After a couple more (very short) rides I hit a large problem, it would run for 5-10mins and then die. Lose all power. But after a few more kicks, more often than not, it would start up and be good for another 5-10mins. I have done a bit of maintenance. New air filter (crumbling), new reed valves (cracked), new spark plugs (very fouled), cleaned out all the jets (some were blocked), and also all fresh fluids. The pistons seem fine, the exhaust is clear, the power valves are in good nick and move smoothly, fresh charged battery.

I'm running out of ideas guys, and would appreciate any help or advice. Oh by the way, it runs clean and smooth now, but it will still die after 5 or 10mins

Please help me

**Ixion** · 21st November 2006, 21:39

Cleaned the tap?

**Reevesy** · 22nd November 2006, 05:59

Sorry,

as it says I'm kinda new to all this, there is a tap?

**Kflasher** · 22nd November 2006, 06:04

Could be something as simple as your fuel tank breather blocked, or old oil causing probs (this would involve stripping and cleaning the oil feed lines etc) I had KR1s a few years back, great bike changed the sprokets tho to keep up with the RGV's, but wicked fun...try to keep front wheel on the deck once she is running fine...

**Donor** · 26th November 2006, 13:11

Not a ceramic resistor getting too hot by any chance?

Assuming it has one... beats me, I'm mechanically challenged with bikes... but that was a favourite on the old Datsun's and puscorts we had coming into the (cage) workshop moons ago...

**xwhatsit** · 26th November 2006, 13:32

He means the fuel tap on the tank. If it's running for 5-10 minutes then dying a possible cause for that would be that it's running out of fuel, the tank can't feed it to the carbs fast enough because the fuel tap is dirty. Check the fuel lines as well, if they're rubber then they can get shitty and blocked quite easily.

**ZorsT** · 27th November 2006, 14:02

It might also be that your coil is faulty. A CT110 that my brother had had that problem.

**F5 Dave** · 27th November 2006, 16:22

90% Not the coil as it starts up after 5-10 min. When half dead coils get hot & go off they take an age to un-short themselves. As above + my fav is the kink in the fuel line if inline filter fitted.

Get your hands dirty, very easy to work on.

**oyster** · 27th November 2006, 18:56

We often have similar problems with Rg 150's that have sitting around for a while. The older brew of 96 octane fuel has / had all sorts of horrible resinlike stuff that doesn't evaporate, so instead it kind of varnishes the inside of the tank. We used to clean all the fuel system, but this only gave relief for a short while, an hour or two of running. It's because this crap is still keeps coming from the tank, over time and running vibration etc.

First of all, confirm your basic problem by running a hose from as close to carbs as possible and running the fuel into a container. Sometimes it'll flow well for a minute then dry up. If it does, then open the fuel cap. If the flow takes off again you know you have a cap venting problem, more common that you'd think. Short term I've solved this by placing a small cable tie or lock wire across the rubber gasket face then closing the cap. This leaves a definite but small breathing hole till you get home (or finish a race meeting) and you can fix properly later.
If the flow is slow from the start, then clean out tap / filter etc, try again to check re cap etc (as above). To clean the tank inside if it's rusty/dirty/"resined" put a handful of nuts and bolts in with some petrol and shake the tank in all directions for ten minutes or till your well stuffed. Then flush out all the rubbish. If fuel starts peeing out thru little holes along the bottom of the tank you a new problem, a rotten tank!!! Best to find out now of course. Use a magnet to get all the nuts and bolts out. I know people who keep a few ball bearings in their tank permanently to be sure any dirt particles are ground up before getting near a filter.
Be very careful with such things on high performance two strokes. The hat trick can be leaning off causing engine seizure, causing crash, causing much pain to bike and rider!

**xxblackbirdxx** · 30th November 2006, 14:36

1) Your tank needs to breathe and it does so usually from a system implemented in to the fuel cap, sometimes the sealing rubber or gasket moves and blocks the hole causing a vaccum and detering the fuel from flowing down to your carbs.
2) Check your float in the carb, sometimes due to varying reasons the float setting could have moved allowing only limited quantity of fuel to settle in the bowl, in this case the rate at which the bike consumes fuel is greater than the rate at which fuel is flowing in to the bowl .. hence it starves.
3) does this bike come with a fuel pump? if yes you might want to check that it works properly.
4) the guy before me has already mentioned the tap so i wont get in to it.
If none of these work , please write back, we cant have a biker not enjoying his pride and joy ..rock on.. best of luck to get it sorted